My fiancé and I are getting married on NYE. Our wedding is small (about 50 guests) and we asked all of the members of our bridal party already. My fiancé’s best friend lives in another state and is a single father to a 2.5 year old girl. The mom is in the picture, but the daughter lives with the dad. My fiancé asked his friend to be the best man and he said he cannot commit to it as it's too far in advance to ask the girl's mom or his parents to watch his daughter and he doesn't want to bring her as he'd be too distracted (understandable). My fiancé even offered to pay for the best man's flight out here since money is tight for him. My fiancé has a guy he’d like to ask if his best friend cannot come (he does not like uneven sides, I don’t mind) but I told him at a certain point it’s going to look rude to ask the backup (he asked the rest of them over two months ago and the backup is aware of this). How long should he wait on the potential best man to give him an answer?